What's Shaking? (Updated)

People who road out Irene are saying warnings were overblown, as if government and MSM were trying to hide something.
My family arrived in Anchorage, Alaska, just months after the huge earthquake in 1964. It never forgot what I saw. Too young then to understand much, I was delighted to find, the last time I took college classes, my campus had the entire report from the US Geological Survey on that event — a whole shelf of binders with tons of drawings, photos and advanced mathematical formulas. I tried to read the whole thing. While I quickly got intellectually buried by the math, everything else made sense to me. In the process, I came to understand the basic physics of tectonics and how earthquakes affect things on the surface.
Let me tell you: That earthquake in Virginia a few days ago was no natural event. That is the signature of a very large explosion. Most quakes show up on seismographs with a distinct pattern. It starts with a strong Primary Wave (P) pattern, followed a bit by Secondary Waves (S) — vertical compression waves followed by vertical rolling waves. Finally, there is a set of surface waves that shake things apart because they are horizontal. That thing in Virginia had no P waves separate from the S waves. It all struck at once, and there were no significant follow-on tremors so far. There are always tremors, sometimes before, and certainly after, but it’s exceedingly rare for them to wait this long.
So far as I know, there is no precedent in the history of seismography for calling that a natural earthquake. The announcements very authoritatively said right away the thing was pretty shallow, about 500 feet. That’s unheard of, so shortly after they changed the story. I think the first estimate was correct, though. That was a subsurface nuke, if you ask me. All we need is confirmation of some serious activity in that area sometime before the quake. A close up satellite view places it out in the woods, if the coordinates are correct, but it doesn’t have to be a straight down drilling.
Update: I stand corrected. There have been small aftershocks. However, I note this fact was only a small part of the bigger picture. As noted by others, it’s the pattern of aftershock placement which matters most. In this case, all the aftershocks have been within a very short radius from the original shake, in an area with no active faults. All that tells us is there is no fault line involved in the shake, and all the aftershocks are subterranean shifts near the original shock. Thus, it does not hinder my assertion it could have been man made.